1. Field of the Invention
This invention relates to a socket for a ball point pen suitable for use with low viscosity aqueous ink, and more particularly to a socket for a ball point pen which is designed to deliver a proper amount of ink quickly from an ink cartridge to a writing ball when the cartridge is inserted into the ball point pen.
2. Description of the Prior Art
Most of the prior art ball point pens using aqueous ink have the ink reservoir in the barrel filled with aqueous ink. When therefore, a long period of time passes before the ball point pen is actually used after being manufactured, the ink held in the ink passageways provided in the socket to connect the writing ball with the cartridge often becomes so dry as to flow with great difficulty or not at all when the user is going to commence writing, rendering the ball point pen utterly unavailable for practical application. To eliminate the above-mentioned difficulties accompanying most of the ball point pens using aqueous ink, there has been developed such type of ball point pen as is designed to be fitted in use with a cartridge filled with aqueous ink. With a known ball point pen, however, the ink passageways provided in the socket are so narrow that under natural conditions, the ink held in the cartridge is delivered only by capillary action to the writing ball through the passageways. Therefore, the aforesaid developed type of ball point pen has the drawback that ink takes too long to reach the writing ball after the cartridge is inserted into the pen body, preventing the pen from being immediately put to use. For quick ink delivery, the user often manually squeezes the ink-filled cartridge fitted into the socket after removing the pen body in order to apply pressure on the ink held in the cartridge. With a general ball point pen, however, a clearance between the writing ball and the edge of the tip portion of the socket is smaller than in the ordinary ball point pen using viscous ink, preventing the air remaining in the ink passageways from easily escaping out of the ball point pen through the forward end of the socket. As a result, the air itself exerts a resistive force within the ink passageways, not only obstructing the quick influx of fresh ink thereinto, but also preventing the ink already held in the passageways from being delivered to any proper outlet due to the prevalence of the air resistance. Accordingly, the ink is unavoidably forced out of the pen body through an air duct provided at the forward end of the pen barrel, undesirably wetting the forward end.